mammal

noun

mam·​mal ˈma-məl How to pronounce mammal (audio)
: any of a class (Mammalia) of warm-blooded higher vertebrates (such as placentals, marsupials, or monotremes) that nourish their young with milk secreted by mammary glands, have the skin usually more or less covered with hair, and include humans
mammalian adjective or noun
mammal-like adjective
or less commonly mammallike
mammal-like behavior
mammallike reptiles

Examples of mammal in a Sentence

Human beings, dogs, and cats are all mammals.
Recent Examples on the Web On Sunday, the Virginia Aquarium & Marine Science Center Stranding Response Program, which coordinates responses for all marine mammals and sea turtles that come ashore in Virginia, arrived and pulled the whale up the beach to be monitored overnight, the aquarium confirmed to USA TODAY. USA TODAY, 4 Mar. 2024 For nearly a month, orcas have been swimming off Southern California, feasting on dolphins and attracting people to see these majestic mammals in nature. Laylan Connelly, Orange County Register, 25 Feb. 2024 The new study also revealed why the noise that humans make in the ocean is so disruptive and harmful for the large mammals. Erin Clack, Peoplemag, 25 Feb. 2024 Also, as the only flying mammals, bats must deal with the enormous stresses that flight exerts on their cells, from rapid increases in body temperature to damage to their DNA. Juergen Eckhardt, Forbes, 22 Feb. 2024 Though none of these incidents involved direct harm to any humans, the belligerent behavior caused a stir, prompting many to once again question the threat marine mammals pose to humans. Max Bennett, Discover Magazine, 21 Feb. 2024 The enormous marine mammals head north each year to feed at sea for four to seven months, with males and females heading to different destinations, rangers said. Don Sweeney, Sacramento Bee, 22 Feb. 2024 The egg-laying mammals also have to contend with predators, which can include hawks, eagles, Tasmanian devils, snakes and dingoes. Christian Thorsberg, Smithsonian Magazine, 20 Feb. 2024 How Humans Generate Heat Like all mammals, humans use chemical reactions in our bodies to keep our internal temperature toasty, and consistently so. Max Bennett, Discover Magazine, 8 Feb. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'mammal.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

from base of New Latin Mammalia (Linnaeus), class name, noun derivative from neuter plural of mammālis, from Latin mamma "breast, udder" + -ālis -al entry 1 — more at mamma entry 1

First Known Use

1811, in the meaning defined above

Time Traveler
The first known use of mammal was in 1811

Dictionary Entries Near mammal

Cite this Entry

“Mammal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mammal. Accessed 19 Mar. 2024.

Kids Definition

mammal

noun
mam·​mal ˈmam-əl How to pronounce mammal (audio)
: any of a class of warm-blooded vertebrates that include human beings and all other animals that nourish their young with milk produced by mammary glands and have the skin usually more or less covered with hair

Medical Definition

mammal

noun
mam·​mal ˈmam-əl How to pronounce mammal (audio)
: any of the higher vertebrate animals comprising the class Mammalia
mammalian adjective or noun

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